tlaronde%kergis.com@localhost a écrit : > The system is unicore? Nope. i7-4770, four cores, eight threads. > Isn't it simply almost thrashing? Too many > processes (that may even have threads) hence too many context switches > for an unsufficient number of cores? I don't think. This server acts as : - tftpd boot server ; - NIS server ; - NFS server (for mainly two active clients, and three or four idle clients). On client side, disks are mounted with async option. If I restart nfsd with only 16 threads, of course, load average on server doesn't rise until 100, but there is a lot of "server not responding" messages on client sides. For me, bottleneck is between nfs server and disk subsystem. To be honnest, there are a lot of tiny services (local DNS, MX2 with a very little traffic. With not special NFS transations, mean load average remains between 0 and 1 : load averages: 0.32, 0.60, 0.52; up 16+02:46:28 11:28:25 85 processes: 84 sleeping, 1 on CPU CPU0 states: 0.5% user, 0.0% nice, 0.0% system, 0.5% interrupt, 99.0% idle CPU1 states: 0.0% user, 0.0% nice, 0.5% system, 0.0% interrupt, 99.5% idle CPU2 states: 0.0% user, 0.0% nice, 1.0% system, 0.2% interrupt, 98.8% idle CPU3 states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle CPU4 states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle CPU5 states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle CPU6 states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle CPU7 states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle Memory: 7079M Act, 3881M Inact, 49M Wired, 146M Exec, 8854M File, 865M Free Swap: 16G Total, 16G Free / Pools: 3742M Used / Network: 855K In, 4230K Out Locally, on raid5 volume : legendre:[~] > dd if=/dev/zero of=test.dd bs=100m count=10 10+0 records in 10+0 records out 1048576000 bytes transferred in 4.246 secs (246956194 bytes/sec) On Raid1 : legendre# dd if=/dev/zero of=test.dd bs=100m count=10 10+0 records in 10+0 records out 1048576000 bytes transferred in 3.291 secs (318619264 bytes/sec)
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